This invention relates generally to a differentiated services network and more particularly relates to propagating status information in a differentiated services network from an egress edge router to an ingress edge router.
Increasing competition requires that service providers, such as ISPs, offer scalable, differentiated services that support their customers existing and emerging business applications. Service providers must not only differentiate among applications but also aggregate the traffic and then set priorities directly related to the latency, throughput, loss and jitter application requirements.
Differential service mechanisms allow service providers to allocate varying levels of services to users. Broadly speaking, this includes any traffic management or bandwidth control mechanisms that treats different users differently. However, in common Internet usage, the term is coming to mean any relatively simple, lightweight mechanism that does not depend entirely on pre-flow resource reservation.
FIG. 1 shows a differentiated service network 10 that includes an egress edge router 80, an ingress edge router 50 and core routers 22, 24, 26 and 28. As is commonly known, the differentiated services network 10 implements a differentiating method between different data packets. The different treatment of the packets may be implemented by marking data packets at the edge of the network, such as the ingress edge router 50, and subsequently treating the data packets via other mechanisms within the network. The ingress edge router 50 preferably marks the data packets for the differential service and the core routers 22, 24, 26 and 28 in the interior of the network execute the specific treatment based on the marking.
The treatment of the data packets may be determined by a set of rules at the ingress edge router 50. The rules may be composed of a value statement and an action to be performed. The set of rules is commonly called a profile, policy or service level agreement. These rules may be a contract between the customer and the network operator that specifies the quality of service (QoS), the customer requirements and the cost associated with that service. The profile may be administrated through an entity known as the bandwidth broker 12 (also called the policy server). However, the administration of profiles does not take into consideration the knowledge of the active network status and therefore cannot adequately respond to dynamic network conditions.
The present invention may provide a method for propagating status information through a network, such as a differentiated services network. The network may include a first edge router (or node), a second edge router (or node), a first core router (or node) and a second core router (or node). The method may include obtaining status information at the first edge router. The first edge router may then propagate a first status message to the first core router. The first core router may update the first status message based on the status information at the first core router. The first core router may then propagate the first status message to a second core router where it may be updated based on the status information of the second core router. The first status message may then be propagated to the second edge router where it may be updated based on the status of the second edge router.
Even further, the first status message may be updated at the second edge router based on a status of the second edge router. The first status message may include a plurality of classes and a status of each of the classes.
The present invention may also include altering operation of the network based on status information at the second edge router.
The present invention may additionally obtain status information at a third edge router, and propagate a second status message from the third edge router to the first core router. The second status message may be updated based on status information at the first core router. The second status message may be propagated to the second edge router.
Still further, the first status message may propagate from the first edge router to the second edge router based on routing tables of the network. The first status message may be altered by status information at each node (or router) as the first status message propagates from the first edge router to the second edge router.
The present invention may also provide a network having a first edge router (or node), a second edge router (or node), a first core router (or node), a second core router (or node) and a controlling device. The controlling device may control the network and make decisions regarding data flow in the network. The network may operate such that status information is propagated from the first edge router to the second edge router along a propagation path. The propagation path may proceed from the first edge router to the second edge router based on routing tables of the network (i.e., reverse path of the routing tables). The status information may be updated at each router (or node) between the first edge router and the second edge router.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description taken in conjunction with the annexed drawings which disclose preferred embodiments of the invention.